Is Cloud Signal Loss Common?

[+drossdross]

I traveled to a geocache under clear skies. When I got there, the narrow valley knocked out the signal - that I expected. But it clouded before I walked out - light clouds. On the way out, I couldn't pick up the sattelites in exact places I had before (down to my same footprints). Will thin clouds knock out the signal? This surprised me. Would batteries effect the pickup - they were colder (60 F) when I finished (76 F when I started)? I have Garmin Legend. Devin

[crr003]

from what I have read - no.

 

What was the time difference between going in and coming out? If you were using different sats, the coords/reception would be different. I have noticed following the breadcrumb track back out it can be off by a long way.

 

Nil Satis Nisi Optimum

[+Searching_ut]

I've never encountered any problems that were weather related, other than rain and snow when in heavy canopy, then it's the trees that cause the problems.

 

Problems in canyons however is common. As the sats move about, sometimes you can receive from several, other times you can't get a fix at all. It all depends on where the sats are in relation to the smaller portion of the sky you can receive. You'll often encounter multipath problems as well which can make your receiver do some weird things

 

For what it's worth

 

Jeff

[Kerry.]

NO, nothing to do with clouds.

 

Being a dynamic system and depending on the time between time in and time out those sats that were there on the way in ain't going to be there (exactly) on the way out.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[+drossdross]

The time difference was about an hour, and the area effected was a trail about 200 yards with checks as far as 20' off trail (all in a valley). I had clean signals all the way in. I had nothing on the way out.

 

If I did lose a critical satellite, roughly (typically) how long will it take to pick up a new one(s)? Are the GPS satellite orbits such that there are spots that getting enough satellites in sight for coordinates is rare?

 

Will fresh NiCad batteries improve reception (with their slightly higher voltage and good cold tolerance)? Or is reception largely independent of battery voltage until it actually drops to zero?

 

Devin

[Kerry.]

An hour is certainly enough for things to go from real good to real bad and that's without the effect of obstructions etc.

 

It's a possibility that simply based on the direction of travel and holding the receiver in front of the body could cause the whole satellite reception pattern to be diffderent.

 

It's like facing south (towards the equator) in the northern hemishpere as there's generally (depending on ones latitude to some extent) really no satellites to the north that the body can obstruct but facing north then that's a different situation all together.

 

Can be very dynamic but if you've got a specific date, time and location then it's not difficult to see what what was going on. Obstructions now they're important as well.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[+drossdross]

Now that I've conducted more searches, I'm finding a good deal of effect from body shielding. I can hold the unit close to me and with a slow rotation often lose the signal. The unit works fine through car window glass though. Wonder if that says something about me?

 

What does your comment about having specifics yeilding an answer to what's going on? Sounds like you know of a neat web site or something

[Kerry.]

NO, no neat website that does very specific and detailed analysis regarding all the variables but there is software that does this.

 

The offer was if you had a specific date/time/location then one can look at what's going on exactly at that time and around that time. Sometimes this can highlight just what the problem/issue might be.

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go